Using control group designs, two procedures will be evaluated in terms of their impact on the long-term treatment compliance of children experiencing orthodontic treatment. The youngsters in both investigations will be receiving orthodontic treatment regimens which involve the use of bionators. A bionator is a removable functional appliance which is designed to guide growth of the lower jaw, as well as, guide the eruption of teeth into more desirable positions. In order for the appliance to be effective, the child must wear it approximately 20 hours per day. Study 1 will investigate the impact on compliance of two different wear schedules for introducing children to the device. The experimental subjects will be asked to wear their bionator according to a schedule which gradually increases the length of time the device is worn daily to full time at the end of three weeks. Control subjects will be given standard orthodontic treatment instructions and told to begin wearing the device full time from day one. Measures of compliance will include daily parent observaton, pterygoid muscle response, plaque build-up on the youngsters' bionators, and the orthodontic assessment of changes in over-bite and overjet (degree of malocclusion). This study is designed to determine the best manner (reduce patients complaints about the device and increase treatment adherence) in which to introduce children to wearing removable appliances. Study 2 will investigate the impact of teaching parents and their children behavior management skills on long-term orthodontic treatment adherence. Control group children will be asked to wear their bionators according to the wear schedule developed in study 1. Similarly, experimental subjects will be exposed to the gradual wear schedule. However, they will also be given training in behavior management skills. The children and their parents will develop reward programs to reinforce the youngsters for performing their orthodontic health care regimens. It is hoped that these studies will determine whether the serious problem of children's orthodontic treatment noncompliance can be modified by altering the manner in which children are introduced to using removable functional appliances. The impact on long-term compliance and rate of orthodontic related parent-child conflict of teaching parents behavior management skills in conjunction with changing the method of introducing bionator treatment will also be examined.